JPH0153688B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a copolymer of 1-acetoxy-1,3-butadiene and an unsaturated compound monomer copolymerizable therewith. Conventionally, copolymers of 1-acetoxy-1,3-butadiene have been produced by bulk polymerization or solution polymerization using azobisisobutyronitrile or benzoyl peroxide as a radical polymerization initiator, or by using persulfate as a radical polymerization initiator. It was obtained by carrying out emulsion polymerization at a high temperature of 60 to 90°C. (For example, Macromol.Chem., 176(2), 341.1975) However, copolymers obtained by conventional methods have a number average molecular weight of
It has been reported that at most only 20,000 can be obtained. Furthermore, when emulsion polymerization is carried out at high temperatures as in the cited literature, not only is the polymer colored yellow to red, which poses a practical problem, but depending on the polymerization conditions, the ester groups may undergo hydrolysis and undergo significant deterioration. It has the disadvantage of being stored away. The copolymer of 1-acetoxy-1,3-butadiene is a copolymer of conjugated diene with a polar group, and various developments can be considered as a new polymer material. Colored copolymers are limited in use and have poor practicality. The present inventors have conducted extensive research on the polymerization method of 1-acetoxy-1,3-butadiene and an unsaturated compound monomer copolymerizable with it, and have found that it is possible to polymerize 1-acetoxy-1,3-butadiene using emulsion or suspension polymerization at low temperatures. -1,
The present invention was achieved by discovering that a highly useful copolymer can be obtained which is suitable as a method for polymerizing 3-butadiene and an unsaturated compound monomer copolymerizable therewith. That is, the present invention provides 1-acetoxy-1,3-butadiene, which is characterized by emulsion or suspension polymerization in the presence of a radical polymerization initiator at -15 to 50°C, and an unsaturated compound monomer copolymerizable with the same. This is a method for producing a copolymer with a polymer. According to the present invention, conventional 1-acetoxy-1,
Compared to the method for producing a 3-butadiene copolymer,
No coloration and almost no hydrolysis1
A copolymer of -acetoxy-1,3-butadiene can be obtained. Furthermore, according to the present invention, copolymers of 1-acetoxy-1,3-butadiene with various molecular weights ranging from low molecular weight to high molecular weight can be obtained. ~
This is a production method suitable for obtaining a copolymer of 1,000,000 1-acetoxy-1,3-butadiene. Next, the present invention will be explained in detail. 1-acetoxy-1,3-butadiene, the monomer used in the present invention, can be obtained by acetoxylating butadiene in the presence of a noble metal catalyst such as palladium, or by converting crotonaldehyde into acetoxylate in the presence of acetic anhydride and an acetate of an alkali metal. It can be obtained by heating at The 1-acetoxy-1,3-butadiene obtained by these reactions is a mixture of the cis form and the trans form, but the monomer used in the present invention can be either the cis form or the trans form alone. It may be a mixture of any of these. Further, it may contain impurities to the extent that it does not cause any inconvenience. 1-Acetoxy-1,3-butadiene can be copolymerized with many unsaturated compound monomers in any ratio, and as unsaturated compound monomers, ethylenically unsaturated compounds and diolefinic unsaturated compounds Compounds can be mentioned. Examples of ethylenically unsaturated compounds include aromatic vinyl compounds such as styrene, α-methylstyrene, monochlorostyrene, vinyltoluene, and methoxystyrene, monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, itaconic acid, fumaric acid, Dicarboxylic acids such as maleic acid and their monoesters, alkyl acrylates or methacrylates in which the alkyl group has 1 to 12 carbon atoms, vinyl cyanide compounds such as acrylonitrile and methacrylonitrile, vinyl chloride, vinylidene chloride, vinyl methyl ethyl ketone, vinyl methyl Ether, vinyl acetate, allyl acetate, methalyl acetate, acrylamide, methacrylamide, vinylpyridine, glycidyl acrylate, glycidyl methacrylate, and the like are preferably used from the viewpoint of polymerizability. As the diolefin-based unsaturated compound, for example, butadiene, isoprene, chloroprene, etc. are preferably used. These unsaturated compound monomers copolymerized with 1-acetoxy-1,3-butadiene are used to improve various properties of the copolymer, such as heat resistance, water resistance, oil resistance, mechanical properties, and adhesive properties. It is used depending on the purpose. Generally, polymerization is carried out so that the amount of 1-acetoxy-1,3-butadiene copolymerized is 1% by weight or more. When the copolymerization amount of 1-acetoxy-1,3-butadiene is 1% by weight, 1-acetoxy-1,3
- Difficult to exhibit the characteristics of butadiene copolymers. Polymerization is carried out at -15 to 50°C, which is lower than the conventional temperature of 60 to 90°C. In order to carry out polymerization smoothly, it is necessary to select an initiation system. As the radical polymerization initiator, persulfates such as ammonium persulfate and potassium persulfate, so-called redox radical polymerization initiators, peroxides, azo radical polymerization initiators, etc. can be used, but from the viewpoint of polymerization rate, polymerization In order to perform this process smoothly, redox radical polymerization initiators or azo radical polymerization initiators with good low-temperature decomposition properties, such as 2,2'-azobis(4-methoxy-
2,4-dimethylvaleronitrile), 2,2'-azobis-(2,4-dimethylvaleronitrile), and the like are preferred, and among these, redox-based radical polymerization initiators are particularly preferred. As conventionally known, redox-based radical polymerization initiators include peroxides such as hydrogen peroxide, cumene hydroperoxy, diisopropylbenzene hydroperoxide, and paramenthane hydroperoxide, and reducing agents that are activators. For example, ferrous salts such as ferrous sulfate are used in combination with oxygen scavengers such as aliphatic polyamines and sulfites.
Per 100 parts by weight, peroxide is 0.001 to 10 parts by weight,
Reducing agent: 0.001 to 1.0 parts by weight, oxygen removing agent: 0 to 1.0 parts by weight
Although parts by weight are used, they can be appropriately selected depending on the polymerization conditions. In emulsion polymerization using a redox-based radical polymerization initiator, for example, a monomer is emulsified in an aqueous system in the presence of an appropriately selected surfactant, and in the presence of the redox radical polymerization initiator, the monomer is emulsified as necessary. Add electrolytes, PH regulators, polymerization regulators, etc. to -15~
Polymerization is carried out at 50°C, preferably -5 to 20°C. In addition, it is also possible to use persulfates, peroxides, or azo compounds as radical polymerization initiators, and carry out emulsion or suspension polymerization at -15 to 50°C in the same way as when using redox-based radical polymerization initiators. It is. In this case, too, at a high polymerization temperature of 60 to 90°C, polymerization stability is poor and it is difficult to obtain a product with a high molecular weight, and the copolymer may be colored or the monomer may undergo hydrolysis and turn into crotonaldehyde. or the copolymer is hydrolyzed,
Industrially useful copolymers of constant quality cannot be obtained. Further, at a polymerization temperature lower than -15°C, a sufficient polymerization reaction rate cannot be obtained. However, by setting the polymerization temperature to -15 to 50°C, preferably 20 to 45°C, these drawbacks can be greatly improved.
Especially when using an azo radical polymerization initiator,
Suspension polymerization is preferably carried out at 20-45°C. Examples of surfactants include so-called anionic surfactants such as _C12 to _C18 fatty acid soaps, disproportionated rosin acid soaps, sodium alkylarylsulfonates, and sodium alkylnaphthalenesulfonates;
The surfactant may be either a nonionic surfactant or an anionic/nonionic surfactant, and of course a mixture of these may be used. The surfactant is usually used in an amount of 0.1 to 10 parts by weight per 100 parts by weight of the monomer. Radical polymerization initiators such as persulfates, peroxides, and azo compounds other than redox-based radical polymerization initiators are
It is usually used in an amount of 0.01 to 10 parts by weight per 100 parts by weight of the monomer. Potassium chloride, sodium phosphate, sodium sulfate, etc. are used as electrolytes as necessary for smooth polymerization, and monomers are usually
0.001 to 1 part by weight is added per 100 parts by weight. In order to adjust the degree of polymerization, long-chain alkyl mercaptan, diisopropylsantogen disulfide, carbon tetrachloride, etc. can be used, and are usually used in an amount of 0.01 to 10 parts by weight per 100 parts by weight of the monomer. Water may contain impurities to the extent that they do not interfere, and may contain organic solvents such as methanol and acetone to the extent that they do not inhibit emulsification or suspension. Polymerization is usually carried out using 50 to 1000 parts by weight of water per 100 parts by weight of the monomer, but this is not particularly limited. In such polymerization, monomers, polymerization aids, etc. may be added all at once, and it goes without saying that an inkjet method may be used if necessary. The polymerization may be carried out up to a polymerization rate of 100%, but depending on the purpose, such as preventing gelation of the copolymer, a polymerization terminator or the like may be added to stop the polymerization midway. The copolymer can be recovered from the reaction system after the completion of the polymerization reaction by various means. For example, the copolymer can be recovered by adding the above reaction system to a large amount of methanol to precipitate it, and the purified copolymer can be recovered by washing thoroughly with methanol and drying. Polymers can be obtained. According to the present invention, 1-acetoxy-
A copolymer of 1,3-butadiene can be obtained. This copolymer has excellent oil resistance and adhesive properties, so it can be used in various fields that take advantage of these characteristics. The present invention will be specifically described below with reference to Examples. Example 1 In a separable glass flask with a capacity of 1,
5g of sodium lauryl sulfonate in 400g of _N2 sewage
and 7 g of sodium dodecylbenzenesulfonate were dissolved, and while stirring, 200 g of the mixed monomer shown in Table 1 in which 0.7 g of tertiary dodecyl mercaptan was dissolved was added and emulsified at 8°C. 0.04 g of sodium hydrogen sulfite was charged into this. Additionally, 0.1 g of sodium ethylenediaminetetraacetate, 0.2 g of ferrous sulfate, and 0.1 g of sodium formaldehyde sulfoxylate were charged. While stirring thoroughly at 8° C., 4 g of paramethane hydroperoxide was charged and polymerized for 10 hours. Thereafter, 2.0 g of N,N-diethylhydroxylamine was added to stop the reaction. In all cases, emulsions without coagulum were obtained. The polymerization rate is shown in Table 1. When this emulsion was added dropwise to the methanol in Step 3 while stirring, a white copolymer was precipitated. In the spectrum of this copolymer measured using an infrared spectrophotometer, no absorption of hydroxyl groups due to hydrolysis was observed. Example 2 In a 600 ml glass pressure bottle, 50 g of 1-acetoxy-1,3-butadiene and 50 g of styrene under _N2 .
g, water 200g, sodium dodecylbenzenesulfonate 5.0g, ferrous sulfate 0.02g, sodium alkylnaphthalene sulfonate 0.15g, ethylenediaminetetraacetate 0.1g, sodium dimethylsulfoxylate 0.1g, cumene hydroperoxide 0.1g , tertiary dodecyl mercaptan
0.2 g was charged and polymerized at 0°C for 24 hours, resulting in an emulsion with a polymerization rate of 72% and no coagulum. When this product was purified in the same manner as in Example 1, a colorless copolymer was obtained, and no hydrolysis occurred. Example 3 In a 600 ml glass pressure bottle, 50 g of 1-acetoxy-1,3-butadiene and 50 g of styrene under _N2 .
g, 200 g of water, 5 g of sodium dodecylbenzenesulfonate, 0.1 g of ammonium persulfate, and 0.5 g of tertiary dodecyl mercaptan, and heated at 42℃.
The reaction was allowed to proceed for 20 hours. An emulsion with almost no coagulum was obtained, and the polymerization rate was 84%. When the copolymer was purified in the same manner as in Example 1, it was found to be a white copolymer, with almost no hydrolysis occurring. Example 4 Polymerization was carried out in the same manner as in Example 3, except that 1.0 g of 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) was used instead of ammonium persulfate. A coagulum-free emulsion with a polymerization rate of 76% was obtained, and the purified copolymer was free from coloration and did not undergo hydrolysis. Comparative Example 1 Polymerization was carried out in exactly the same manner as in Example 3 except that the reaction temperature was changed to 60°C. The polymerization system contained many coagulated substances, and the copolymer was brown in color. 【table】

Claims (1)

[Claims] 1. In the presence of a radical polymerization initiator at -15 to 50°C,
1-acetoxy-1,3-butadiene is characterized by emulsion or suspension polymerization of 1-acetoxy-1,3-butadiene and an unsaturated compound monomer copolymerizable therewith.
A method for producing a copolymer of 1,3-butadiene and a monomer copolymerizable therewith. 2. The manufacturing method according to claim 1, which uses a redox radical polymerization initiator.